The iontophoresis (Acta Dermatol venereol, vol. 64, page 93, 1984) and the electroporation (a published Japanese Publication of International Patent Application No. 3-502416, Proc. Acad. Sci. USA, vol. 90, pages 10504 to 10508, 1993) are processing methods of introducing a drug or a physiologically active substance into an organism from a skin or a mucous membrane using electric energy. In addition, there is a method of extracting a diagnosis substance from an organism to observe a condition of the organism using the same principle as those methods (Nature Medicine, vol. 1, pages 1198 to 1201, 1995). In such a method, an electrode device is required in order to apply electric energy. The electrode device generally includes a recess for putting gel of polymer molecules and the like including an electrolyte.
Japanese Patent Laid-Open No. 2000-316991 discloses an idea of making this type of electrode device having a recess disposable as opposed to an external power supply device that is used repeatedly. Japanese Patent Laid-Open No. 2000-316991 proposes a form in which a substrate film including an outward flange section, which surrounds a recess opened upward and a periphery of the opening of the recess, and a lead section, which extends from the outward flange section, and an electrode layer leading to the lead section from a bottom and a sidewall of the recess through the outward flange section on the substrate film are provided and gel containing a drug and the like is arranged on the electrode layer in the recess. The gel or a conductor in the recess is sealed by a cap member covering the recess. In use, the cap member is peeled and brought into contact with an organism. The cap member is adhered to the flange section of the substrate film and seals the recess in a sealed state.
Incidentally, it has been found that, when such an electrode device having a recess is produced in large quantities, there are technical problems as described below. A first problem is prevention of disconnection of an electrode layer. In the electrode layer that extends from the bottom of the recess to cross a step, disconnection tends to occur in the step portion of the recess. It is considered that a main cause of the disconnection is stress (stress caused by a difference between elongation of the substrate film and elongation of the electrode layer involved in the formation) at the time when the recess is molded.
In addition, as another problem, there is prevention of leakage of the gel from the recess and improvement of seal strength of the cap member. In order to bring the cap member into contact with the organism surely, it is necessary to fill the gel in the recess (that is, to the height of the outward flange section). Thus, it is highly likely that leakage of the gel is caused. In turn, the leakage causes decrease in the seal strength of the cap member.